Abstract: A telescopic jib of a load-handling device, having telescopically extensible sections in the form of fluid cylinders. An annular sealing assembly is employed at the end portions of the sections, in the form of a sleeve which defines an annular space with the end face of the fluid cylinder of greater diameter and the side surface of the fluid cylinder of smaller diameter. A floating ring is mounted in the annular space and has seals which engage the external periphery of said smaller-diameter fluid cylinder and the end faces of the floating ring. Annular grooves are coaxial in the external peripheral surface at the end of each said fluid cylinder and in the end face of the respective one of said sleeves such that, a support ring is accommodated in each pair of annular grooves. A rope-and-sheave system having at least two runs symmetrically extending with respect of the longitudinal axis of the jib is used to govern the motion of the sections.

Abstract: The disclosed mechanical arm comprises a base having mounted thereon a plurality of pivotally connected links, each having its own individual motor operatively connected through driving kinematic chains with said links, and a tensioning mechanism including a tensioning member and kinematic chains connecting said tensioning member with the links; said tensioning mechanism being provided with differential gears in a number equalling that of said driving kinematic chains tensioned by said tensioning member, one output of each said differential gears being connected to said individual motor, and two other outputs thereof being connected to the preceding and successive ones of said differential gears; the two unoccupied outputs of the terminal ones of said differential gears being connected, respectively, to said base and said tensioning member.The invention is primarily intended for automation of main and auxiliary operations in various industries, e.g. for handling of production tools and equipment.